Transcript Fertilizing

Fertilizing
Plant Material Maintenance
Fertilizing
Essential elements
 Nutrient deficiency symptoms
 Fertilizer forms
 Interpreting labels
 Application techniques
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17 Essential Elements (Nutrients) for
Woody Plant Growth
Elements Derived From Air and
Water
Carbon (C)
 Oxygen (O)
 Hydrogen (H)
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Soil - Macronutrients
Nitrogen (N)
 Phosphorous (P)
 Potassium (K)
 Calcium (Ca)
 Magnesium (Mg)
 Sulfur (S)
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Soil - Micronutrients
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Boron (B)
Chlorine (Cl)
Copper (Cu)
Iron (Fe)
Manganese (Mn)
Molybdenum (Mo)
Nickel (Ni)
Zinc (Zn)
Nutrient Deficiencies
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Lack of either macro or micro nutrients will impede normal plant
growth.
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Not enough in the soil
In the soil, but unavailable
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Symptoms will appear on different parts of the plant. Interpret these
symptoms.
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Some common nutrient deficiencies and the symptoms:
Nitrogen deficiency
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Older leaves (bottom of plant) begin to
yellow. Remainder of plant generally a
lighter green than normal.
 Nitrogen
is mobile in the plant and can be
translocated to new, young leaves.
 Nitrogen can be mobile in the soil.
Phosphorous deficiency
Leaves often dark green.
 Veins, petioles, and lower surfaces may
become reddish – purple colored.
 Sparse, distorted foliage.
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 Phosphorous
is mobile in plants.
 Phosphorous is immobile in the soil.
Potassium deficiency
Marginal and interveinal chlorosis followed
by scorching moving inward between the
main veins.
 Leaf curling
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 Potassium
is highly mobile in plants.
 Potassium is immobile in the soil.
Iron deficiency
 Interveinal
Chlorosis: Veins stay green, but area
between veins turns yellow.
 Common on pin oak, red maple and river birch.
 Due to high pH soil.
 Common problem in Iowa, especially on trees planted
where original topsoil has been removed. (New
subdivisions)
 Iron cannot be translocated.
Organic Fertilizer
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Organic fertilizer
 Derived
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from plant and animal products.
Blood meal, bone meal, manure & sewage sludge.
fert. released slowly – avoids plants from
being burned.
 Generally more expensive than chemical fert. on the
basis of amount of nutrients supplied.
 Organic fert can work as a soil amendment at the
same time.
 Organic
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Ex. Milorganite
Inorganic Fertilizer
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Manufactured chemical fertilizer.
Much more concentrated than organic.
 Can
burn plants with too much fert, especially if using
a fast release form.
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Less expensive.
Carbon (C) : Nitrogen (N) Ratio
The ratio of carbon atoms to nitrogen
atoms.
 Soil microorganisms use nitrogen to
metabolize (breakdown) carbon.
 Certain types of organic matter are very
high in carbon:
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Sample C:N of various types of organic matter:
Sandy loam (fine)
Humus
Food scraps
Alfalfa hay
Grass clippings
Rotted manure
Sandy loam (coarse)
Vegetable trimmings
Oak leaves
Leaves, varies from
7:1
10:1
15:1
18:1
19:1
20:1
25:1
25:1
26:1
35:1 to 85:1
Peat moss
Corn stalks
Straw
Pine needles
Farm manure
Alder sawdust
Sawdust weathered 3 years
Newspaper
Douglas fir bark
Sawdust weathered 2 months
58:1
60:1
80:1
60:1 to 110:1
90:1
134:1
142:1
170:1
491:1
625:1
Nitrogen Robbing
Organic matter with excess C:N ratios (or
excessive amounts of organic matter) can
create problems.
 To continue decomposition the soil
microorganisms will draw nitrogen out of
the soil making it unavailable to plants.
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Fertilizer Forms
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Liquids
 Easy
application (tank mix or hose end sprayer).
 Potential to burn plants if mixed too strong, or too
much applied.
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Soluble Powder
 Dissolves
readily in water (apply just like liquid).
 Generally less expensive than liquid.
Fertilizer Forms
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Granular
 Most
common and widely used form.
 Slow release forms available.
Prolongs release of nutrients
 Decreases burning potential
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Fertilizer Labels
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Analysis
 Shows
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type of nutrients and amount.
Nitrogen – Phosphate – Potash
 N-P-K
 10-5-5
Gives the percentage of each in the fertilizer.
 10% Nitrogen, 5% Phosphate, 5% Potash
 Use conversion factors to find % phosphorous and
potassium.
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Conversion Factors
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To convert phosphate to phosphorous (P):
 Multiply
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%phosphate by .44
To convert potash to potassium (K):
 Multiply
%potash by .83
Osmocote fertilizer label
What’s the analysis of the fertilizer?
 19-5-8
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What percentage of the fertilizer is N?
 19%
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What percentage of the fertilizer is
phosphate (P2O5)?
 5%
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What percentage of the fertilizer is potash
(K2O)?
 8%
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What percentage of the fertilizer is actual
phosphorous (P)?
5
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x .44 = 2.2%
What percentage of the fertilizer is actual
potassium (K)?
8
x .83 = 6.64%
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How long is this fertilizer supposed to last
at 70 degrees F.?
 8-9
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months
Does this fertilizer contain any
micronutrients?
 Yes
How many forms of N are in the fertilizer?
3
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 6.60%
Ammoniacal Nitrogen
 5.70% Nitrate Nitrogen
 6.70% Urea Nitrogen
Application Methods
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Broadcast on the soil surface
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Most soils supply adequate amounts of nutrients with the exception of N.
 Effective method for applying N.
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Placed in holes in the soil
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P, K and other nutrients of low solubility benefit from incorporation.
 Core, punch, or drill holes.
 6 inches deep, 2-3 feet apart.
Application methods continued
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Injected into the soil under pressure
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High pressure hydraulic sprayer.
 6 inches deep.
 150-200 psi pressure.
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Sprayed on foliage
Placed in holes in tree trunks
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Micronutrient implants.
 Placed in xylem.
 Holes approx. ½ inch in diameter.
 Plug holes.
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Injected into the trunk
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Micronutrients.
 Mauget, Wedgle.
Broadcast Application of
Fertilizer
Fertilizer Application in Holes
Injecting Fertilizer into the Soil
150-200 psi
Foliar Fertilizer Spray
Misting sprayer suitable
for foliar feeding
Systemic Tree Implants
Microinjection:
How to use Mauget
Microinjection:
Wedgle direct inject system
Macroinjection
Fertilizer Math
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Remember that a 20 -10 -10 fertilizer, for example, contains only 20%
actual N on a weight basis. A useful calculation for determining how many
pounds of fertilizer to apply is:
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pounds of fertilizer = application rate of the nutrient in pounds
percentage of that nutrient in the analysis
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If you want to apply nitrogen at the rate of 2 pounds per 1,000 square feet to
an area measuring 300 square feet how many pounds of 20 – 10 – 10
fertilizer should be applied:
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pounds of fertilizer = application rate of the nutrient in pounds
percentage of that nutrient in the analysis
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pounds of fertilizer =
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10
1,000
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x = 3 pounds
=
x
300
2 = 10 pounds of fertilizer
.20
The End